Liquid oral pharmaceutical compositions for oral administration have been often formulated in the past in vehicles which contain ethanol. Frequently, the compositions thusly prepared do not contain water because of a stability problem, to suppress undesirable organoleptic properties of the composition or to enhance solubility.
Ibuprofen is a non-steroidal anti-inflammatory (analgesic) drug whose family is known in the art as NSAID's. It has been on the ethical and proprietary markets for years and is in widespread use. While many dosage unit forms of the compound are on the market, few acceptable oral, one phase liquid forms of ibuprofen have been reported. U.S. Pat. No. 4,684,666, U.S. Pat. No. 3,228,831 and U.K. Patent Specification 971,700, are representative of the prior art.
Due to the low solubility of ibuprofen in aqueous vehicles and its poor organoleptic characteristics, certain of us earlier found excellent oral dosage units can be prepared using a vehicle comprising certain edible oils and absolute ethanol. However, now a new problem has been identified.
Ibuprofen, and other NSAID's which have a reactive carboxylic acid moiety in their chemical structures, have been unexpectedly found to form ethyl ester derivatives in the oral edible oil-alcohol vehicles.
Esterification can reduce the quantity of ibuprofen available for absorption. The alcohol-oil vehicles remain, however, excellent products organoleptically when formulated with NSAID active ingredients. The following description will describe a solution we have found to this previously unrecognized problem in the art.